title: Duplicated superficial femoral veins: a source of error in the sonographic investigation of deep vein thrombosis.
abstract: OBJECTIVE
  To determine whether the number of false-negative ultrasound (US) findings of thrombosis is larger when a duplicated femoropopliteal venous system is present.
  
  
  METHODS
  A retrospective review was performed of 381 venograms obtained after initial US findings were considered negative for thigh or popliteal thrombosis in patients in whom deep vein thrombosis was suspected Venograms were evaluated for the presence of thrombosis and the presence and configuration of duplicated superficial femoral veins.
  
  
  RESULTS
  Multiple superficial femoral veins were present on 177 (46%) of the 381 venograms; 149 (84%) were duplex systems. False-negative US findings occurred in four (2%) of 204 patients with single femoral veins and in 10 (6%) of 177 patients with duplicated femoral veins (P = .056, not statistically significant).
  
  
  CONCLUSIONS
  The frequency of missed proximal thrombosis at sonography appears to be increased when duplicated superficial femoral veins are present. Data from clinical and imaging studies are insufficient to support the adoption of a totally noninvasive imaging strategy.
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, Cambridge, England.
authors.forename: N J
authors.initials: NJ
authors.lastname: Screaton
authors.forename: J H
authors.initials: JH
authors.lastname: Gillard
authors.forename: L H
authors.initials: LH
authors.lastname: Berman
authors.forename: P M
authors.initials: PM
authors.lastname: Kemp
mesh_terms: D000013:Congenital Abnormalities / Q000000981:diagnostic imaging / Q000453:epidemiology; D003287:Contrast Media; D003951:Diagnostic Errors; D005188:False Negative Reactions; D005260:Female; D005268:Femoral Vein / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D015994:Incidence; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D010690:Phlebography; D011152:Popliteal Vein / Q000000981:diagnostic imaging; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D014463:Ultrasonography / Q000706:statistics & numerical data; D018608:Ultrasonography, Doppler / Q000706:statistics & numerical data
chemical_list: D003287:Contrast Media; D007479:Iopamidol